Despite effective current therapies for Type 1 diabetes (T1D), significant risks of long term complications of diabetes exist. Multiple studies have demonstrated that autoimmunity associated with type 1 diabetes is found years before its clinical presentation and that T1D can be predicted. The goals of the Type 1 Diabetes TrialNet Study Group are to prevent loss of beta cells through study of the pathogenesis of T1D and trials of therapies to intervene in the process. To reach TrialNet's goal, successful Clinical Centers must maintain and develop highly effective recruitment approaches, encourage participation of subjects in follow up and prevention studies and carry out studies in a highly efficient and accurate manner. In addition, they must contribute to the overall mission by engagement in TrialNet activities and committees and adding clinical and/or scientific expertise. The aims of this application reflect our center's approach to meeting TrialNet's mission: ? To describe the progress and function of the Toronto Clinical Center as an innovative and effective TrialNet site that has developed an extensive regional and national network with broad links in the diabetes community. As a result, our site ranks 5th of 18 Clinical Centers in the number of subjects enrolled in screening and monitoring phases of the Pathway to Prevention study with a very high retention rate of over 90%. Careful analysis of the effectiveness of recruitment approaches through the use of reports from TrialNet's Coordinating Center and data collected by our site has allowed us to optimize efforts yielding an increase in the number of subjects screened for the Pathway to Prevention Study over the past 3 years. ? To illustrate leadership and collaborative roles in TrialNet efforts such as Dr. Wherrett's leadership of the Study of Effects of Recombinant Human Glutamic Acid Decarboxylase on the Progression of Type 1 Diabetes in New Onset Subjects Study, management of all Canadian regulatory requirements for our site and the Canadian Affiliate Network, and our coordinators' roles in developing materials to support recruitment. ? To highlight approaches used to assist Affiliate Sites with training and specialized support such as screening event identification and development. Methods to enhance recruitment and cost efficiency through new links, optimize efficiency of IRB review through the development of shared tools for review and consent documents, monitor the success of recruitment efforts and study conduct are detailed. A proposal for a fellowship to support new clinical researchers in type 1 diabetes is described.